War. Environmental collapse.Natural disasters: Writing from the near future, a sci-fi master imagines our Doomsday: "Using World Model 2035 as a shared starting condition, we’ve seed-slotted a thousand general doom scenarios. Groups are already forming to team-reify them. So join one, bringing your biases and special skills. Or else, start your own doomsday scenario, no matter how crackpot! Is Earth running out of phlogiston? Will mole people rise out of the ground, bent on revenge? Later, we’ll let quantum comparators rank every story according to probabilities..."